DFT calculations and MD simulation were used to analyse the corrosion inhibition activity and mechanism of N,N′-(1,4-phenylene)bis(1,1-di(pyridin-2-yl)methanimine) (PBDPM), and the structure–activity relationship was tested. The results from SEM and water contact angle and potentiodynamic polarisation curve measurements verify the adsorption behaviour of PBDPM on the surface of mild steel, and test that PBDPM plays a role in corrosion inhibition by changing the hydrophilic and hydrophobic properties of the surface of mild steel. (Image credit: Xiaolong Li.)